This invention relates in general to crankshaft dampers. More specifically, this invention relates to a dual mode damper that is mounted on an engine crankshaft and dampens torsional and axial vibrations.
One type of crankshaft damper is known as a dual frequency torsional vibration damper. This type of damper includes two inertial masses and two elastomeric elements. The elastomeric elements and masses are tuned (by geometry and material selection) to dampen two different torsional frequencies.
Another type of crankshaft damper is known as a dual mode damper. This type of damper includes two masses and two elastomeric elements. The elastomeric elements and masses can be tuned (by geometry and material selection) to dampen axial and/or torsional vibrations.
When an engine crankshaft is rotated, elastomeric members and damping masses of crankshaft dampers counteract vibrations that occur. Typical crankshaft dampers include a hub and a rim. It is known to position elastomeric members and damping masses within an axial inner surface of the rim. This construction obstructs a spoke region of a crankshaft damper, thus inhibiting the performance of service.
This invention includes a crankshaft damper having a damping mass that is mounted away from a spoke region so that service can be performed on the installed crankshaft damper. Furthermore, this invention includes a crankshaft damper that dampens both torsional and axial vibrations transmitted by an engine crankshaft.
In a preferred embodiment, a crankshaft damper includes a hub and a rim. The rim has an outer diameter greater than an outer diameter of the hub. A plurality of spokes connects the rim to the hub. An axial inner surface is formed on the rim and projects forwardly of the spokes. A damper support includes a band and a collar. The band is retained to the axial inner surface of the rim and the collar projects radially outwardly beyond the outer diameter of the rim. An elastomeric member is mounted on the collar and faces the rim. A damper is mounted on the elastomeric member and faces the rim. The elastomeric member and damper are positioned radially beyond the rim to dampen torsional and axial vibrations.